Some bacteria can absolutely live independently of a host. These are called free-living bacteria. They obtain their nutrients from the environment, such as soil, water, or decaying matter. They don't need a host to survive and can reproduce on their own.

Other bacteria are called obligate parasites. This means they absolutely require a host to survive. They can't obtain nutrients or reproduce on their own. These bacteria rely on their host for food, shelter, and sometimes even for the right temperature and pH for their survival.

There are also facultative parasites. These bacteria can survive both with and without a host. They may prefer a host environment, but they can still thrive on their own if necessary.

So, the answer is: it depends. Some bacteria can definitely live without a host, while others need a host to survive.